Bulk solidifying amorphous alloys are a recently discovered family of amorphous alloys, which have a number of physical attributes that make them highly useful in a wide range of applications. For example, bulk solidifying amorphous alloys can sustain strains up to 1.5% or more without any permanent deformation or breakage. Furthermore, they have a high fracture toughness of 10 ksi-sqrt(in) (sqrt: square root) or more, and preferably 20 ksi sqrt(in) or more. Also, they have high hardness values of 4 GPa or more, and in some formulations as high as 5.5 GPa or more. The yield strength of bulk solidifying alloys ranges from 1.6 GPa and reaches up to 2 GPa and more exceeding the current state of the Titanium alloys. Furthermore, the above bulk amorphous alloys have a density in the range of 4.5 to 6.5 g/cc, as such they provide high strength to weight ratios. In addition to desirable mechanical properties, bulk solidifying amorphous alloys also have very good corrosion resistance.
However, bulk-solidifying amorphous alloys have a few short comings as well. Generally, amorphous alloys have lower Young (and shear) Modulus compared to their crystalline counterparts. For example, Ti-base amorphous alloys typically have a modulus 10 to 25% lower than the leading Ti-base alloys. As such the stiffness to weight ratio of bulk amorphous alloys is not favorable, and as such limits the use and application of such alloys in designs where stiffness is the primary factor. Another shortcoming of amorphous alloys is the limited toughness and energy absorption capability of these materials which reduces their resistance to impacts, especially when their thickness exceeds 2 mm or more. Still another shortcoming of amorphous alloys is a lack of resistance to crack propagation, which substantially reduces the fatigue life of amorphous alloys.
Accordingly, a need exists for improved formulations of bulk solidifying amorphous alloys having improved physical properties.